The 1989–90 Australian region cyclone season was an above average

tropical cyclone A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depend ...

season. It was also an event in the ongoing cycle of

formation. It ran from 1 November 1989 to 30 April 1990. The regional tropical cyclone operational plan also defines a ''tropical cyclone year'' separately from a ''tropical cyclone season'', and the "tropical cyclone year" ran from 1 July 1989 to 30 June 1990. Tropical cyclones in this area were monitored by four

Tropical Cyclone Warning Centre A Regional Specialized Meteorological Centre (RSMC) is responsible for the distribution of information, advisories, and warnings regarding the specific program they have a part of, agreed by consensus at the World Meteorological Organization as p ...

s (TCWCs): the

Australian Bureau of Meteorology Australian(s) may refer to: Australia * Australia, a country * Australians, citizens of the Commonwealth of Australia ** European Australians ** Anglo-Celtic Australians, Australians descended principally from British colonists ** Aboriginal Aus ...

Perth Perth is the capital and largest city of the Australian state of Western Australia. It is the fourth most populous city in Australia and Oceania, with a population of 2.1 million (80% of the state) living in Greater Perth in 2020. Perth is ...

, Darwin, and

Brisbane Brisbane ( ) is the capital and most populous city of the states and territories of Australia, Australian state of Queensland, and the list of cities in Australia by population, third-most populous city in Australia and Oceania, with a populati ...

; and TCWC

Port Moresby (; Tok Pisin: ''Pot Mosbi''), also referred to as Pom City or simply Moresby, is the capital and largest city of Papua New Guinea. It is one of the largest cities in the southwestern Pacific (along with Jayapura) outside of Australia and New Z ...

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

Seasonal summary

ImageSize = width:825 height:205 PlotArea = top:10 bottom:80 right:20 left:20 Legend = columns:3 left:30 top:58 columnwidth:270 AlignBars = early DateFormat = dd/mm/yyyy Period = from:01/07/1989 till:01/05/1990 TimeAxis = orientation:horizontal ScaleMinor = grid:black unit:month increment:1 start:01/07/1989 Colors = id:canvas value:gray(0.88) id:GP value:red id:TD value:rgb(0.5,0.8,1) legend:Tropical_Disturbance/Tropical_Depression_(TD) id:C1 value:rgb(0,0.98,0.96) legend:Category_1_=_63–87_km/h_(39–54_mph)_(1) id:C2 value:rgb(0.80,1,1) legend:Category_2_=_88–142_km/h_(55–74_mph)_(2) id:C3 value:rgb(1,1,0.80) legend:Category_3_=_143–158-km/h_(75–98_mph)_(3) id:C4 value:rgb(1,0.56,0.13) legend:Category_4_=_159–204_km/h_(99–127_mph)_(4) id:C5 value:rgb(1,0.38,0.38) legend:Category_5_=_≥205_km/h_(≥128_mph)_(5) Backgroundcolors = canvas:canvas BarData = barset:Hurricane bar:Month PlotData= barset:Hurricane width:10 align:left fontsize:S shift:(4,-4) anchor:till from:14/07/1989 till:16/07/1989 color:C1 text:"02S (C1)" from:04/11/1989 till:13/11/1989 color:C2 text:"Pedro (C2)" from:13/12/1989 till:20/12/1989 color:C3 text:"Felicity (C3)" from:04/01/1990 till:17/01/1990 color:C1 text:"Rosita (C1)" from:11/01/1990 till:21/01/1990 color:C3 text:"Sam (C3)" from:24/01/1990 till:29/01/1990 color:C2 text:"Tina (C2)" from:26/01/1990 till:04/02/1990 color:C2 text:"Nancy (C2)" barset:break from:25/02/1990 till:06/03/1990 color:C3 text:"Vincent (C3)" from:28/02/1990 till:05/03/1990 color:C1 text:"Greg (C1)" from:04/03/1990 till:13/03/1990 color:C2 text:"Walter-Gregoara (C2)" from:04/03/1990 till:07/03/1990 color:C2 text:"Hilda (C2)" from:14/03/1990 till:26/03/1990 color:C5 text:"Alex (C5)" from:14/03/1990 till:26/03/1990 color:C4 text:"Ivor (C4)" from:11/04/1990 till:18/04/1990 color:C1 text:"Bessi (C1)" bar:Month width:5 align:center fontsize:S shift:(0,-20) anchor:middle color:canvas from:01/07/1989 till:01/08/1989 text:July from:01/08/1989 till:01/09/1989 text:August from:01/09/1989 till:01/10/1989 text:September from:01/10/1989 till:01/11/1989 text:October from:01/11/1989 till:01/12/1989 text:November from:01/12/1989 till:01/01/1990 text:December from:01/01/1990 till:01/02/1990 text:January from:01/02/1990 till:01/03/1990 text:February from:01/03/1990 till:01/04/1990 text:March from:01/04/1990 till:01/05/1990 text:April TextData = pos:(569,23) text:"(For further details, please see" pos:(713,23) text:"

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number w ...

Systems

Tropical Storm 02S

Tropical Storm 02S existed from July 14 to July 16.

Tropical Cyclone Pedro

At 0:00 UTC on November 6, the BOM detected an area of low pressure within a monsoonal trough near 7.8°S, 97.2°E., which gradually organized while drifting westward for the next couple of days. On November 8, the disturbance strengthened into a tropical cyclone and was named ''Pedro''. The cyclone continued to intensify before reaching its peak intensity at 13:00 UTC on November 10 with 10-minute sustained winds of around 70 mph (110 km/h) and a minimum pressure of 982 mbar (28.99 inHg), with a short-lived eye visible on satellite imagery. As Pedro moved southward, strong vertical wind shear left the low-level center bare and displaced convection to the northwestern side of the storm. At 0:00 UTC on November 13, Pedro's winds weakened below gale-force and the system degenerated into a remnant system, which dissipated the following day. Pedro passed within 85 miles (140 km) of

Cocos Island Cocos Island ( es, Isla del Coco) is an island in the Pacific Ocean administered by Costa Rica, approximately southwest of the Costa Rican mainland. It constitutes the 11th of the 13 districts of Puntarenas Canton of the Province of Puntarenas ...

, where a peak wind gust of around 85 mph (137 km/h) was recorded. At least 7.9 inches (202 mm) of precipitation fell on the island within a 24-hour period, causing localized flooding. A palm plantation and loading wharf were damaged by the storm.

Severe Tropical Cyclone Felicity

On 13 December, the BoM started to monitor a monsoon low, that had developed within the

Arafura Sea The Arafura Sea (or Arafuru Sea) lies west of the Pacific Ocean, overlying the continental shelf between Australia and Western New Guinea (also called Papua), which is the Indonesian part of the Island of New Guinea. Geography The Arafura Sea is ...

to the northeast of Darwin. Over the next day, the system moved southeastwards over the Northern Territory, before it re-curved slightly and entered the

Gulf of Carpentaria The Gulf of Carpentaria (, ) is a large, shallow sea enclosed on three sides by northern Australia and bounded on the north by the eastern Arafura Sea (the body of water that lies between Australia and New Guinea). The northern boundary is ...

. Early on 15 December, the system was named Felicity by TCWC Brisbane, after it had become a category 1 tropical cyclone on the Australian Scale. During that day the JTWC initiated advisories on the system and designated it as Tropical Cyclone 07P, with peak 1-minute sustained wind speeds of 110 km/h (70 mph). TCWC Brisbane subsequently reported peak 10-minute sustained wind speeds of 110 km/h (70 mph), before the system made landfall over the

Cape York Peninsula Cape York Peninsula is a large peninsula located in Far North Queensland, Australia. It is the largest unspoiled wilderness in northern Australia.Mittermeier, R.E. et al. (2002). Wilderness: Earth’s last wild places. Mexico City: Agrupación ...

where it weakened below cyclone intensity. The system subsequently moved into the Coral Sea during 16 December, where it started to rapidly deepen, but did not reattain the classical characteristics of a tropical cyclone. As a result, both TCWC Nadi and TCWC Brisbane treated the system as a tropical depression over the next four days despite winds of between being observed in the southwest quadrant. Felicity subsequently dissipated during 20 December as it was absorbed by a short-wave trough of low pressure to the north of New Zealand. Some minor damage to vegetation was recorded on the Cape York Peninsula.

Tropical Cyclone Rosita

Rosita was first noted as a low-pressure system at 18:00 UTC on January 4 while it located well south of

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...

. Moving swiftly westward, the disturbance gradually organized for two days until slightly weakening due to increasing vertical

wind shear Wind shear (or windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizontal ...

. The system remained quasi-stationary until January 9 when a developing ridge in the middle-latitudes forced the disturbance northwestward. The low was ill-defined with a weak and sheared structure on satellite imagery while moving equatorward. By 6:00 UTC the following day, convection began to redevelop and consolidate through January 12 as the disturbance strengthened. At 15:00 UTC on January 13, tropical storm-force winds formed around the center, prompting the BOM to upgrade the low into ''Tropical Cyclone Rosita''. The nascent cyclone tracked south-southeastward, remaining under the influence of vertical wind shear causing majority of convection to be displaced west of the center. Rosita once again changed course late the next day, shifting northwestward as it lost gale-force winds. The remnants tracked around the periphery of the more intense Severe Tropical Cyclone Sam, before moving equatorward and dissipating on January 17.

Severe Tropical Cyclone Sam

Sam, 11 to 21 January 1990, near Western Australia

Tropical Cyclone Tina

Tina, 24 to 29 January 1990, crossed Western Australia

Tropical Cyclone Nancy

In late January, a monsoon trough spawned a tropical depression on 26 January, over the

Coral Sea The Coral Sea () is a marginal sea of the South Pacific off the northeast coast of Australia, and classified as an interim Australian bioregion. The Coral Sea extends down the Australian northeast coast. Most of it is protected by the Fre ...

. The depression developed good outflow, before gaining tropical cyclone characteristic on 31 January, and was designated as ''Tropical Cyclone Nancy''. An upper-level trough forced the storm southward, before shifting southwestward. At 3:00 UTC on 1 February, Nancy reached its peak intensity with 10-minute sustained winds of around 60mph (110 km/h) and a minimum pressure of 975 mbar. Between 1–2 February, the cyclone gradually moved just offshore the

area. Nancy then weakened while continuing to move southward, before transitioning into an extratropical low on 4 February. The remnants eventually dissipated to the west of

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

on 8 February. Nancy caused flash floods responsible for five fatalities.

Severe Tropical Cyclone Vincent

Vincent, 25 February to 6 March 1990, near Western Australia

Tropical Cyclone Greg

Greg, 28 February to 5 March 1990, Gulf of Carpentaria

Tropical Cyclone Walter–Gregoara

Walter, 3 to 27 March 1990, Indian Ocean

Tropical Cyclone Hilda

Cyclone Hilda had cloud tops estimated at tall. The measured cloud top temperature was which is the coldest cloud-top temperature ever measured.

Severe Tropical Cyclone Alex

Alex was a fairly intense system. It existed from 14 to 26 March 1990. Despite the intensity, Alex never caused significant damage.

Severe Tropical Cyclone Ivor

Ivor, 14 to 26 March 1990, crossed Cape York, Queensland

Tropical Cyclone Bessi

Bessi, 11 to 18 April 1990, Indian Ocean

Season effects

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Notes

References

{{DEFAULTSORT:1989-90 Australian region cyclone season Australian region cyclone seasons

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